In large-scale fruit packing operations, such as apple packing houses, fruit is prepared for shipping in packing lines. The fruit is placed into lightweight packing trays made of molded pulp, plastic or the like. The trays filled with fruit are then loaded into boxes for shipment.
Apple trays are made in different sizes to accommodate different sizes of apples. The trays are shaped to contain fruit-holding pockets into which the fruit is placed. The size of an apple tray, by convention, refers to the number of apples per bushel box. For different size apples, the size and number of the fruit-holding pockets is different on the trays. Also by convention, the overall outer dimensions of every size of apple tray are the same or very similar, which permits all of the different sizes of apples to be packed in a standard-sized shipping box. Normally, apple trays are rectangular and have length and width dimensions of 19.5 inches and 12 inches, respectively. These sides of a standard apple tray are referred to herein as the "long" sides and the "short" sides of the tray.
Apple trays are sold to apple packing houses in nested stacks. In a packing operation, trays are dispensed from the nested stacks either manually or by machine and are individually fed to a conveyer belt, where they are transported through the packing line and filled with apples. At the end of the packing line, the filled trays are loaded into shipping boxes. The packing line can convert from packing one size of apple to a different size of apple by changing the size of the apple trays being dispensed into the packing line.
Apparatus exist in the art for individually delivering items from a nested stack, such as fruit trays, egg cartons, and the like onto a conveyer. Exemplary disclosures from the prior art include U.S. Pat. No. 4,328,908 to Temming; U.S. Pat. No. 4,789,291 to Allan; U.S. Pat. No. 3,341,072 to van der Schoot; U.S. Pat. No. 3,283,955 to Crabtree; U.S. Pat. No. 3,283,952 to Burt; and U.S. Pat. No. 3,297, 201 to Burt.
The fruit tray denesting apparatus used in the art have a number of shortcomings. For example, in some prior art apple tray denesting machines, the trays are loaded upside down into the dispenser, and each tray must be flipped over (as it is fed or before it is fed) onto the conveyer. This manner of operation has proven to be problematic in use.
In a different apparatus currently in use, apple trays are fed from a nested stack to the conveyer without being overturned. This apparatus makes contact with integrally-formed and identically-located structures provided on the long sides of the trays specifically for the purpose of contact with the denesting apparatus. Due to the nonuniformity in shape of different size apple trays along the long sides of the tray, and the fact that not all tray styles provide specific engagement areas on the long sides of the trays with which contact is made, this device performs with some but not all of the different styles of apple trays which are available. Moreover, since this apparatus works by grasping the trays at the long sides of the trays, there can be interference between the grasping means and the conveyer. In operation, the grasping means of this device actually pass through appropriate openings in the conveyer (and withdraw to below the conveyer after releasing each tray) making each tray-delivering cycle inherently longer and thereby limiting throughput.